1 //===-- LockFilePosix.cpp ---------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Host/posix/LockFilePosix.h"
11 
12 #include <fcntl.h>
13 
14 using namespace lldb;
15 using namespace lldb_private;
16 
17 namespace
18 {
19 
20 Error fileLock (int fd, int cmd, int lock_type, const uint64_t start, const uint64_t len)
21 {
22     struct flock fl;
23 
24     fl.l_type   = lock_type;
25     fl.l_whence = SEEK_SET;
26     fl.l_start  = start;
27     fl.l_len    = len;
28     fl.l_pid    = ::getpid ();
29 
30     Error error;
31     if (::fcntl (fd, cmd, &fl) == -1)
32         error.SetErrorToErrno ();
33 
34     return error;
35 }
36 
37 }  // namespace
38 
39 LockFilePosix::LockFilePosix (int fd)
40     : LockFileBase (fd)
41 {
42 }
43 
44 LockFilePosix::~LockFilePosix ()
45 {
46     Unlock ();
47 }
48 
49 Error
50 LockFilePosix::DoWriteLock (const uint64_t start, const uint64_t len)
51 {
52     return fileLock (m_fd, F_SETLKW, F_WRLCK, start, len);
53 }
54 
55 Error
56 LockFilePosix::DoTryWriteLock (const uint64_t start, const uint64_t len)
57 {
58     return fileLock (m_fd, F_SETLK, F_WRLCK, start, len);
59 }
60 
61 Error
62 LockFilePosix::DoReadLock (const uint64_t start, const uint64_t len)
63 {
64     return fileLock (m_fd, F_SETLKW, F_RDLCK, start, len);
65 }
66 
67 Error
68 LockFilePosix::DoTryReadLock (const uint64_t start, const uint64_t len)
69 {
70     return fileLock (m_fd, F_SETLK, F_RDLCK, start, len);
71 }
72 
73 Error
74 LockFilePosix::DoUnlock ()
75 {
76     return fileLock (m_fd, F_SETLK, F_UNLCK, m_start, m_len);
77 }
78